How to Build a Prediction Market Bot

Technical guide to building automated prediction market trading bots. Includes API integration, strategy implementation, and deployment instructions.

Building a Prediction Market Trading Bot

This guide walks you through creating an automated trading bot for prediction markets. We'll cover architecture, API integration, strategy implementation, and deployment.

Prerequisites

  • Programming knowledge (Python or TypeScript recommended)
  • Understanding of prediction markets and trading mechanics
  • API access to your chosen platform
  • A funded account for live trading (start with paper trading)

Step 1: Choose Your Platform

Select a platform based on API quality, liquidity, and the types of markets you want to trade.

Polymarket - Best liquidity, crypto-native, good API docs

Kalshi - US-regulated, REST API, traditional settlement

Metaculus - For forecasting bots, not trading

Step 2: Bot Architecture

┌─────────────────┐     ┌──────────────┐
│   Data Feeds    │────▶│  Analysis    │
│ (prices, news)  │     │   Engine     │
└─────────────────┘     └──────┬───────┘
                               │
┌─────────────────┐     ┌──────▼───────┐
│   Order Mgmt    │◀────│   Strategy   │
│ (place, cancel) │     │    Logic     │
└─────────────────┘     └──────────────┘

Step 3: Implement Core Components

Data Layer

  • WebSocket connections for real-time prices
  • REST API calls for market info and historical data
  • News/sentiment feeds if using external data

Strategy Layer

  • Signal generation (when to buy/sell)
  • Position sizing (how much to trade)
  • Risk management (stop losses, exposure limits)

Execution Layer

  • Order placement and management
  • Fill monitoring and position tracking
  • Error handling and retries

Step 4: Strategy Examples

Market Making: Place orders on both sides of the book, earning the spread between buy and sell prices.

Arbitrage: Monitor multiple platforms and trade when prices diverge beyond transaction costs.

Model-Based: Use ML/LLM to generate probability estimates and trade when market prices differ from your model.

Step 5: Testing & Deployment

  1. Backtest - Test on historical data to validate edge
  2. Paper trade - Run with fake money to test execution
  3. Small live test - Start with minimal capital
  4. Monitor & iterate - Watch performance, fix bugs, improve
  5. Scale gradually - Increase position sizes as confidence grows

Important Warnings

  • Bots can lose money - especially poorly tested ones
  • API rate limits can break your strategy at critical moments
  • Always have a kill switch to stop the bot if something goes wrong
  • Test error handling thoroughly - networks fail, APIs go down

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